This invention relates to dispensers used in bodies of liquid (particular water) where the liquid level rises and falls. It is particularly well suited to dispensers for cleaning and/or freshening such bodies of water, or containers downstream there from (such as a toilet bowl) which hold the treated water.
A variety of dispensers exists for automatically dispensing one or more chemicals into a water tank. See e.g. U.S. Pat. Nos. 5,924,142; 5,903,930; 5,839,128; 5,718,261; D376,840; 5,551,095; 5,488,742; D365,138; 5,152,015; 5,090,443; 5,038,417; 4,915,260; 4,696,414; 4,663,786; 4,660,231; 4,534,071; 4,429,809; 4,346,483; 4,285,074; 4,189,793; 4,101,043; 3,874,007; 3,778,850; 3,698,021; 2,587,388; and 1,602,554. See also GB 2,167,041; EP 1,026,331; and WO 99/08076. The disclosure of these patents and of all other publications referred to herein are incorporated by reference as if fully set forth herein.
However, such conventional automatic dispensers typically have disadvantages. For example, some have a tendency for the product being dispensed to leak out of the dispenser in an uncontrolled manner at some times, resulting in overdosing (and waste) of the product. Some do not provide adequate control over the amount of product that is dispensed when the water level changes. Still others do not provide the ability to release a cleaning and/or freshening agent so that it is retained in sufficient concentration in a toilet bowl after the flush (to prevent the majority of the active ingredients from being expelled along with the flush water). Moreover, some such dispensers which provide better performance are unduly expensive to produce, and thus are not practical for some applications such as home toilet bowl cleaning.
While a number of automated dispenser systems do use some type of float to follow the water level in a tank to help control the dispensing in response to water level changes, even such float systems have not successfully resolved all of the above concerns. Accordingly, there is a need in the art for an improved dispenser.
In one aspect the invention provides a dispenser for use in a tank that has a liquid level that rises and falls. The dispenser has a container, an adaptor for attachment to the container, a dosing chamber in the adaptor having therein a floating shuttle that can essentially seal a lower opening in the dosing chamber in one mode, and alternatively can float upwardly from that sealing mode, and a floatable valve head positioned outside the dosing chamber for alternately opening and closing the lower opening in the dosing chamber.
In preferred forms the container contains a dispensable product, and the product level in the dosing chamber can control the movement of the floating shuttle in the dosing chamber. There can also be a grommet that is not integral with the dosing chamber that is positioned adjacent the lower opening of the dosing chamber to form a valve seat for the floating shuttle. The grommet can provide a valve seat for the floatable valve head (for example, if the floatable valve head is hemispherical at its upper end the valve seat for the floatable valve head on the grommet can be essentially hemispherical in contour). In a particularly desirable form the grommet can be made of an upper layer of a first material and a lower layer of a second material different from the first such that the valve seat for the floating shuttle is of the first material and the valve seat for the floatable valve head is of the second material. This allows optimization of the softness of the valve seat for the upper layer, while permitting, the lower layer to be made of a material resistant to degradation.
In other forms there can be an air inlet into the container with an air pocket surrounding the air inlet. This prevents gurgling sounds when the product is being dispensed.
The floatable valve head can be surrounded by a reservoir. During a flush cycle water collects in the reservoir and then washes off the product from the valve head to avoid undesired build-ups or clogging.
The container can be a replaceable bottle. An opening in such a container can, after installation, have remnants of a seal that was pierced as the container was associated with the dispenser. When using this type of replaceable bottle, the adaptor preferably has a piercing element above the dosing chamber which pierced the seal. This permits a consumer to install a refill bottle without having the cleaner product splash or spill in an undesired manner. In other forms the container may be made of an essentially rigid plastic with a refilling port.
Alternatively, the container can be a flexible pouch. If so, this avoids certain concerns regarding venting as the container is emptied.
The product may be a liquid or flowable gel, but the shuttle should have a lower specific gravity than that of the product. In this regard, when the shuttle has a lower specific gravity than that of the product, after the valve head reseals the dispenser (at the end of the flush cycle when the toilet tank is refilled), the greater specific gravity of the product will cause it to bleed down into the dosing chamber below the shuttle, to cause the shuttle to float up. This creates an aliquot of product that is ready to be dispensed at the next flush cycle.
Liquid level in the tank will control the position of the floatable valve head relative to its valve seat. This in turn permits changes of product level in the dosing chamber, resulting in movement of the floating shuttle.
In another form the invention provides a method of cleaning a toilet having a water storage tank and a bowl. One inserts into the tank a dispenser comprising a container containing a dispensable product, an adaptor for attachment to the container, a dosing chamber in the adaptor having therein a floating shuttle that can essentially seal a lower opening in the dosing chamber in one mode, and alternatively can float upwardly from that sealing mode, and a floatable valve head positioned outside the dosing chamber for alternately opening and closing the lower opening in the dosing chamber.
The dispenser is configured and positioned such that water level of the tank controls the movement of the floatable valve head, and product level in the dosing chamber controls the movement of the floating shuttle in the dosing chamber. One then flushes the toilet.
For toilet bowl cleaners, any of the known flowable concentrated toilet bowl cleaning materials currently recommended for use in toilet tank water can be used, or others can be developed using surfactants, dyes, fragrances and/or other cleaning agents such as acids and chelating agents. For swimming pools, known flowable pool cleaning and/or water treatment chemicals can be used.
If the dispenser is installed in the tank, and the water level in the tank is at a specified filled level, the floatable valve head is designed to be driven up by the water to a position sealing the lower opening of the dosing chamber. This then allows the product level in the dosing chamber to rise even though the floating shuttle is moved up away from a sealing position. When the water in the tank is lowered or emptied (as would be typical when the toilet is flushed), the valve head will drop down away from sealing the lower opening of the dosing chamber, thereby allowing a dose of product in the dosing chamber to be released from the dispenser.
The dual float and the dosing chamber features of the dispenser help to accurately control the amount of product dispensed during each flush cycle. The fact that the product is delivered during the stage of the flush cycle when the water level is rapidly dropping helps insure that the product is delivered to the bowl at the latter part of the flushing cycle. Thus, most of the cleaner is not quickly flushed down the sewer with the waste. The concentration of cleaner in the bowl water and along the bowl sides between flushes is thus increased.
Further, the device is relatively inexpensive to produce. Also, it is designed so that a consumer can quickly install a refill without splashing or waste.
A more detailed understanding of these and other features and advantages of the present invention can be had by reference to the drawings and to the accompanying description, in which there are illustrated and described preferred embodiments of the invention.